Many different types of fabric conditioning agents have been used in fabric treatment compositions. One class of compounds frequently used as the active component for such compositions includes substantially water-insoluble quaternary nitrogenous compounds having two long alkyl chains. Typical of such materials are ditallow dimethyl ammonium chloride and imidazoline and imidazolinium compounds substituted with two long chain alkyl groups. These materials are normally prepared in the form of an aqueous dispersion.
The use of substituted imidazoline compounds as fabric conditioning agents is known. Imidazoline salts have been used by themselves or in combination with other agents in the treatment of fabrics. British patent specification 1,565,808, Apr. 23, 1980, assigned to Hoechst Aktiengesellschaft, discloses a textile fabric softener composition consisting of an aqueous solution or dispersion of an imidazoline or salt thereof, or a mixture of such imidazolines or salts thereof. The imidazoline disclosed in the Hoechst patent may have one alkyl chain interrupted by an ester linkage. U.S. Pat. No. 4,724,089, Feb. 9, 1988, to Konig et al., discloses fabric treatment compositions containing dialkyl imidazoline compounds, or salts thereof, which may have one alkyl chain interrupted by an ester linkage. U.S. Pat. No. 4,806,255, Feb. 21, 1989, to Konig et al., discloses an aqueous fabric conditioning composition comprising a di(higher alkyl)cyclic amine and a quaternary ammonium softening agent having two higher alkyl groups linked to the quaternary nitrogen atom. U.S. Pat. No. 4,661,269, Apr. 28, 1987, to Trinh et al., discloses rinse-added liquid fabric softening compositions containing the reaction products of higher fatty acids and polyamines, cationic nitrogenous salts having only one long chain acyclic aliphatic hydrocarbon group, and optionally cationic nitrogenous salts having two or more long chain acyclic aliphatic hydrocarbon groups or one said group and an arylalkyl group. One potential reaction product of a higher fatty acid and polyamine includes an imidazoline ester compound.
The use of both imidazolinium amide and imidazolinium ester salts as fabric conditioning agents is also known. U.S. Pat. No. 2,874,074, Feb. 17, 1959, to Johnson discloses using imidazolinium salts to condition fabrics. The disclosed imidazolinium salts may have one alkyl chain interrupted by an ester linkage. U.S. Pat. No. 3,689,424, Sep. 5, 1972, to Berg et al., discloses detergent compositions containing a textile softener composition which may contain quaternary ammonium compounds containing two alkyl groups. One of the quaternary ammonium compounds disclosed is a substituted imidazolinium salt with one alkyl chain interrupted by an ester linkage. U.S. Pat. No. 3,681,241, Aug. 1, 1972 to Rudy discloses fabric conditioning compositions containing a mixture of amide imidazolinium salts and other cationic fabric conditioning agents. U.S. Pat. No. 4,661,269, Apr. 28, 1987, to Trinh et al., discussed above, discloses as an optional component an imidazolinium amide compound.
U.S. Pat. No. 4,233,451, Nov. 11, 1980, to Pracht et al., and U.S. Pat. No. 4,127,489, Nov. 28, 1978, to Pracht et al., disclose fabric softening compositions containing di-substituted imidazolinium compounds, which may have one alkyl chain interrupted by an ester linkage, in combination with other fabric conditioning agents, including quaternary ammonium compounds having one or two straight chain organic groups with at least 8 carbon atoms.
None of these references, however, disclose combining quaternary imidazoline ester salts with certain other nonionic fabric conditioning agents, such as ester-containing nonionic compounds, and the associated desirable storage-stability, viscosity and fabric conditioning properties realized therein.
It is therefore an object of the present invention to provide a fabric softening and anti-static composition which exhibits improved softener performance and phase stability through the combination of an imidazolinium ester salt and a nonionic fabric conditioning compound.
It is another object of this invention to provide a method for conditioning fabrics with aqueous dispersions containing a quaternary imidazoline ester compound and a nonionic fabric conditioning compound.
It is still another object of this invention to provide a method for conditioning fabrics by treating them with particular textile treatment compositions containing the ingredients described herein and which are in solid form. Such solid compositions are releasably affixed to sheet materials which can be used in hot air clothes dryers.
These objects are realized by the present invention.